bench_blocks.rb

require 'benchmark'

N   = 1_000
ary = (1..10_000).to_a

Benchmark.bm 15 do |x|
  x.report("block") do
    N.times { ary.map { |n| n * 2 } }
  end

  x.report("with object") do
    N.times { ary.each_with_object(2).map(&:*) }
  end

  x.report("method") do
    N.times { ary.map(&2.method(:*)) }
  end
end

__END__
                      user     system      total        real
block             0.760000   0.000000   0.760000 (  0.771719)
with object       1.040000   0.000000   1.040000 (  1.040319)
method            1.290000   0.000000   1.290000 (  1.295140)